This invention generally relates to the art of electrical connectors and, particularly, to a modular jack assembly for use in telecommunications equipment.
Modular jack assemblies are used in telecommunications equipment for mating with telephone-type modular plugs to transmit electrical signals therethrough. A typical modular jack assembly includes a dielectric housing having a receptacle for receiving the modular plug. A plurality of conductive terminals are mounted in the housing, with contact arms cantilevered into the receptacle. A conventional modular jack assembly includes at least eight terminals for engaging eight contacts of the modular plug. A simple eight-terminal modular jack assembly which mates with an eight wire plug is quite reliable and creates few problems.
However, some modular plugs contain only four or six wires, but the four or six wire plugs still are inserted into an eight-wire jack assembly. When this occurs, the outside terminals in an eight-terminal array in the jack assembly are prone to become damaged. This is due to the plastic ends of the plugs outside the four or six wire array contacting some of the jack terminals. The plastic ends cause the terminals to deflect excessively, resulting in a large rotating movement where the terminals are fixed to the jack housing. This large rotational movement causes the terminals to take a permanent set, and those damaged terminals no longer can apply sufficient pressure to the outside wires of a full eight wire modular plug. In addition, with the ever-increasing speed of data transmission, the reduction or elimination of crosstalk has become important for electrical connectors including modular jack assemblies. Crosstalk is a phenomena that occurs when a part of the electromagnetic energy transmitted through one of a plurality of conductors in a connector causes electrical currents in the other conductor or conductors. Various systems have been designed to prevent this crosstalk, such as passing the signals through over-line plates or through traces on a printed circuit board which create a capacitive connection. Heretofore, modular jack terminals have been provided with capacitive plates which were insert molded in the jack housing to maintain registration and location. However, this insert molding process requires a large capital investment.
Still other problems are encountered simply in mounting the tiny modular jack terminals in the very small jack housing. As stated, insert molding is quite expensive for an otherwise simple and inexpensive electrical connector. Mechanically inserting the terminals into the jack housing often results in damage to the tiny and very fragile terminals. The present invention is directed to solving this myriad of problems, including the provision of an improved system for mounting the terminals in the assembly as well as providing a capacitive relationship between the terminals.
An object, therefore, of the invention is to provide a new and improved modularjack assembly of the character described.
In the exemplary embodiment of the invention, the modular jack assembly includes a housing having a plug-receiving receptacle. A terminal module is disposed in the housing and includes a dielectric body mounting a plurality of terminals, with contact portions of the terminals cantilevered from the body into the receptacle. The dielectric body includes a pair of body halves having opposing abutting faces. The terminals have mounting portions embedded in the opposing faces of the body halves. The terminals are securely captured in the dielectric body when the mounting portions of the terminals arc sandwiched between the body halves.
According to one aspect of the invention, the opposing abutting faces of the body halves include a plurality of recesses for receiving the mounting portions of at least some of the terminals. The mounting portions are press-fit into said recesses. The body halves, themselves, have interengaging means for press-fitting the body halves together.
According to another aspect of the invention, the mounting portion of at least one of the terminals in the opposing abutting face of one of the body halves overlaps the mounting portion of one of the terminals in the opposing abutting face of the other body half to create a capacitance arrangement. The overlapping mounting portions may be generally flat plate portions of the terminals. In the preferred embodiment, a dielectric sheet is disposed between overlapping mounting portions of the terminals.
Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings